Thursday

October 30, 2014

October 30, 2014

Number of results: 221

**Diff eqn- IVP**

A simple pendulum of length is oscillating through a small angle θ in a medium for which the resistance is proportional to the velocity. Obtain the differential equation of its motion and discuss the motion.
*March 12, 2011 by shasha*

**Diff eqn- IVP**

The differential equation that governs the forced oscillation is shown below: 0.2 d²y/dt² + 1.2 dy/dt +2y = r(t) where r(t) is the external force. Given that r(t) = 5 cos 4t with y(0) = 0 . find the equation of motion of the forced oscillations
*March 14, 2011 by shasha*

**Diff eqn- IVP**

A particle moves on the x-axis with an acceleration, a=(6t-4)ms⁻1. Find the position and velocity of the particle at t=3 , if the particle is at origin and has a velocity of when t=0
*March 12, 2011 by shasha*

**math**

If h=6, the IVP becomes dP/dt=P(7-P)-6, P(0)=Po Solve the IVP in implicit form though you should apply initial conditions. How small does Po have to be for the population to become extinct in finite time? explain using phase portrait.
*October 16, 2011 by mike*

**algebra 1,urgent**

the expression (4x^2-3x+1)-(x^3+2x+7) what is the coefficient of the x term in the simplified expression? what is an equation of a line parallel to the line with equation 2 y=14-6x a.y=-6x+18 b.y=-3x-9 c.y=6x+3 d.y=3x+8 Solve linear system, which substitution of unkowns is ...
*April 23, 2013 by Sven*

**math**

Consider the eqn x²+2x-n =0 where n€N and n€[5,100]. Total no. Of different values of 'n' so that the given eqn has integral roots is-
*July 5, 2014 by tanu*

**Maths A level**

A large cylinrical tankor radius 40cm contins a liquid and at time,t the depth is h cm. There is a hole in the bottom and liuid leaks out at a rate of 32pi h to power of 0.5. Show at time t, the heighth of the liquid in the tank satisfies the diff. eqn..dh by dt=-0.02 h to ...
*May 23, 2014 by Thomas*

**MATH**

LAMONT IS REQ TO READ 1 BIO, 1 SCIENCE, AND 1 POETRY BOOK EACH MONTH. HIS BOOK CHOICES ARE: 2 DIFF BIOS 3 DIFF SCIENCE 3 DIFF POETRY HOW MANY COMBINATIONS OF REQ BOOKS ARE POSSIBLE?
*January 26, 2009 by lANEY*

**differential**

dT/dt= k(T - Tm), t > 0 where k is a constant of proportionality, T and Tm are measured in degrees Fahrenheit, and time t is measured in hours. Because Diff wants to investigate the past using positive values of time, he decides to correspond t 0 with 6:00 A.M., and so...
*September 27, 2012 by armut*

**Diff eq**

y'(x)=sqrt2y(x)+7, y(4)=1 Solve the seperable diff eq
*February 24, 2013 by Melissa*

**Algebra 1**

1.To solve the linear system below, which substitution of unkowns is proper ? A.substitute 5x-16 for y in the first eqn B.substitute 5x+16 for y in the first eqn C.substitute 5x+12 for y in the first eqn D.substitute 7y-4 for x in the second eqn 2.A line with a slope of -2 ...
*April 18, 2013 by Ley*

**diff eqn.**

y(t) = -0.2451 cos 4t + 0.9804 sin 4t + e^(-3t ) (A cos〖t+B〗 sin〖t)〗 y'(t) = ?
*November 20, 2011 by Farah*

**Science**

Put slice of "potato" in four diff bowls. Add diff "solutions" to each bowl. Which is Dependent Variable and which is Independent Variable?
*October 26, 2011 by LW*

**maths**

The quadratic eqn x²-6x+a=0 and x²-cx+6=0 have one root in common. The other roots of the first and second eqn are integers in the ratio 4:3. Then the common roots is-
*July 5, 2014 by jha*

**Algebra 1**

1. How many solutions does the linear system have ? 3x - y = 4 -3x + 11y = 2 2. A line passes through the points (6,4) and (5,-3). What is the equation of the line in point-slope form ? a. x - 6 = 7(y-4) b. y - 4 = 7(x-6) c. y + 6 = 7(x+4) d. y - 6 = 7(x-4) 3. A line passes ...
*April 19, 2013 by Shevani, help me*

**Math**

LOL I can't figure this out. It should be easy it's been years since I've been in school and my son has no idea. The product of two numbers is 63. Their sum is 16. What are the numbers? Thanks for the help! Let's factor 63. 1 x 63; 3 x 21; 7 x 9. Which of those pairs of ...
*January 17, 2007 by Lisa*

**Physics**

How does the drag force on an object change if the object's area is halved while the wind speed is doubled, while keeping everything else the same? i think it would double if you use this eqn: f= 1/4 A v^2 can someone verify if this eqn is correct to use in this problem?
*October 18, 2009 by Nancy*

**Maths**

In an orthonormal system, you're given the following: Point P(1,2) Lina a=cartesian eqn:4x-3y+6=0 Line b=parametric eqns:x=-5+3& y=-& (real n°) Circle z=cartesian eqn:x²+y²-2x-3=0 (a)Calculate the angle between lines a an b (b)Calculate the coordinates of the point of ...
*May 4, 2008 by Anonymous*

**Mathematics**

In an orthonormal system, you're given the following: Point P(1,2) Lina a=cartesian eqn:4x-3y+6=0 Line b=parametric eqns:x=-5+3& y=-& (real n°) Circle z=cartesian eqn:x²+y²-2x-3=0 (a)Calculate the angle between lines a an b (b)Calculate the coordinates of the point of ...
*May 18, 2008 by Anonymous*

**math**

child's fair ticket is $5 and adult fair ticket are $5. 1050 people attend the fair. fair collects $7350. how many of each type of ticket were sold? sorry. child is $5 and adult is $8 Try this: x = no. of children attending the fair y = no. of adults attending the fair so, 5x...
*February 2, 2007 by gaynell*

**physical science**

if two lighting volts heat exactly they same place at they same time in are frame of ref.,it is possible that observed in other frames will see the volts heating at diff. time r at diff. places????? explain.
*September 25, 2011 by angie*

**chemistry**

If heat of reaction, Ca(s) + 2H+(aq) Ca2+(aq) + H2(g) , is - 544 kJ/mol, heat of reaction, CaO(s) + 2H+(aq) Ca2+(aq) + H2O(l) , is -192 kJ/mol. and heat of formation of water is -286, what is heat of CaO? i found that the formation of CaO is -638. However, I'm confused about ...
*February 11, 2007 by nicholas*

**algebra**

how would i find an equation of a line that goes through points(1,6) and (3,10)?? thanks A straight line is y=mx+b Substitute the points to make two equations. 6=m(1)+b 10=m(3)+b Two equations; two unknowns, m and b. Solve for m and b, then plug back into y = mx + b. That will...
*December 22, 2006 by jasmine*

**math**

a childs bank contains $6.30 in dimes and quarters. there are twice as many dimes as quarters. how many of each kind of coin are in the bank? let d = #dimes and q=#quarters. The total is worth $6.30. eqn 1 is 0.10*d + 0.25*q=$6.30 eqn 2 is 2*#quarters = #dimes or 2q=d. Two ...
*November 29, 2006 by katie*

**Math**

solve the ivp dy/dx = 1/(sqrt(1-x^2)) with initial condition y(sqrt(3)/2)=0
*September 19, 2012 by Mark*

**maths**

1. Identify two examples of exponential r/s 2. The data below shows how the the population of the world has changed over the last three hundred years Year population(mill) 1650 500 1700 600 1750 700 1800 900 1850 1300 1900 1700 1950 2500 2000 7000 The data can be modelled by a...
*February 26, 2007 by me again Thanks sooo much*

**Science ENGR Part 2**

How many electrons are in the upper level? Problem 2 Problem 1 of chapter 6 of the course-pack. Use eqn. 2.27 for the definition of decibel. Eqn. 2.27 : A(w)=-20log|T(jw)| db Use the plot to calculate the repeater distance in a long haul optical communication system. Assume ...
*November 19, 2006 by Pam*

**Algebra 1 HELP PLZ!!!**

Use the Substitution method to solve the system of equations. x + y = -4 x - y = 2 PLz HELP!! I'M NOT BOB BUT I CAN HELP ITS REALLY SIMPLE ALGEBRA X + Y = -4......EQN 1 X - Y = 2.....EQN 2 From EQN 2, let x = 2 + y Substitute that into EQN 1 x - y = -4 (2+y) + y= -4 2 + 2y= -4...
*November 2, 2006 by Margie*

**maths**

Sachin and rahul attempted to slove a quadratic eqn. Sachin made a mistake in writing down the constant term and ended up it roots (4,3). Rahul made a mistake in writing down coefficient of x to get roots (3,2) the correct roots of the eqn are:
*July 5, 2014 by jha*

**Calculus**

Solve the IVP {y'=-(sinx)y + xexp(cosx) y(0) = 1 Please show me step by step. Do I need to find out if this is exact? Do I use an integrating factor?
*October 7, 2009 by Ella*

**Calculus**

A cylindrical drum is made to hold exactly 1m^3 in its interior. Assume that the material for the top and the bottom costs $20 per m^2, while that for the side costs $10 per m^2. Determine the radius of the drum that minimizes the cost of the material used. ____ / \ |\____/| &...
*December 10, 2006 by Frederique*

**algebra**

I have beans that sell for $9 per pound and $12 per pound, they need to be mixed to create 100lbs of mixture that will sell for $11.25 per pound . How much of each type of bean should be used in the mixture? X=#lbs beans that sell for $9.00/lb. Y=#lbs beans that see for $12.00...
*March 20, 2007 by Tony*

**math**

Please help me on this calculus question. I am getting the wrong diff. equation and so my answers to the remaining parts are wrong. ---------------------- A thermometer reading 85 degress outside is brought into a room with a constant temperature of 72 degrees. The rate of ...
*September 29, 2009 by Matt*

**math**

If a,b,c are integers and b²=4(ac+5d²), d €N then roots of the eqn ax²+bx+c=0 are
*July 5, 2014 by tanu*

**math**

Let a,b and c be real numbers such that 4a+2b+c =0 and ab>0. Then the eqn ax²+bx²+cx²=0 has-
*July 5, 2014 by tanu*

**diff eq**

solve 2y^2(y'')+2y(y')^2=1
*February 17, 2013 by jump*

**Diff EQ**

is the integration of (x-2)^2 = 1/3(x-2)^3 Yes, that is correct.
*January 22, 2007 by nicole*

**math**

Show that if roots of eqn (a²-bc) x²+2(b²-ac)x +c²-ab=0 are equal then either b=0 or a³+b³+c³=3abc.
*July 5, 2014 by tanu*

**Reposted - math - Ashley's question**

L=length w=width ============ eqn 1 is 2L + 2w = 28 eqn 2 is w= (1/2)L+2 =========== solve for L and w. Post your work if you get stuck. http://www.jiskha.com/display.cgi?id=1169164168 Posted by Ashley on Thursday, January 18, 2007 at 6:49pm. John made a rectangular pen for ...
*January 19, 2007 by DrBob222*

**engilsh**

diff in fact oppinion
*January 3, 2011 by no name*

**Chemistry**

Plz help me balance this chemical eqn H2C2O4.2H2O+KMnO4 ---->
*November 29, 2011 by Roseline*

**maths**

If 2+i√3 is a root of the eqn x²+px+q=0, where p,q belongs to R, then find the ordered pair (p,q)
*July 5, 2014 by tanu*

**math**

If p,q,r,s belongs to R and pr=2(q+s) then show that atleast one of the eqn x²+px+q=0,x²+rx+s=0 has real roots.
*July 7, 2014 by vaish*

**Math**

What are the steps in finding the diff quotient for f(x)= sq rt of x?
*November 3, 2008 by Kassi*

**Calculus**

A cylindrical drum is made to hold exactly 1m^3 in its interior. Assume that the material for the top and the bottom costs $20 per m^2, while that for the side costs $10 per m^2. Determine the radius of the drum that minimizes the cost of the material used. Any help will be ...
*December 9, 2006 by Fredrique*

**biology**

trying to find the sims and differences for the following --------------------------------------- fertilization v pollination sim's both part of the process of sexual repro diff. pollination doesnt involve direct contact since it is transfer from the anther to the stamens by ...
*July 27, 2009 by Jim_R*

**US history**

what/who did the antifederalists support? (what is diff. from them and the federalist beliefs)
*October 20, 2008 by Samantha*

**computer**

diff between actual and formal parameter
*October 25, 2011 by computer*

**computer**

state diff. between HTML AND DHTML
*June 5, 2012 by Shivansh Tomar*

**algebra- factoring**

given the revenue eqn R(p) =-0.08p^2+300p how do i determine the demand equation?
*July 19, 2010 by Anonymous*

**maths**

The values of 'a' for which the sum of yhe squares of the roots of the eqn x²-(a-2)x-a-1=0 assume the least value is-
*July 5, 2014 by jha*

**Algebra**

Mario is 16 years older than his sister Mercedes. Together, their ages total 36 years. How old is Mercedes? Mercedes is 20 years old. let x = Mario's age y = Mercedes' age ====================== Mario is 16 years older than Mercedes; therefore, add 16 to Mercedes' age to get ...
*December 23, 2006 by Melissa*

**Thermal Physics, Kinetic Theory of Gases**

Oxygen (O2) has a molar mass of 32 g/mol. (e) Suppose an oxygen molecule traveling at this speed bounces back and forth between opposite sides of a cubical vessel 0.10 m on a side. Find the average force it exerts on one of the walls of the container. (Assume that the molecule...
*November 1, 2012 by Help!!*

**Biology - URGENT Enzyme Lab**

Did a catalase producing hydrogen peroxide lab, used manganese dioxide, fresh frozen liver, potato, ice, fine clean sand, etc. Basically just added hydrogen peroxide to the catalysts under diff conditions and stuff. Just dont get this question which is : how do you account for...
*April 5, 2013 by Shreya*

**eng**

whats the diff b/w figure of speech and figurative language?
*January 2, 2008 by BEN*

**social studies**

how is the iroquois confederacy diff. from the colonial government?
*March 25, 2010 by lauren*

**Diff EQ**

Find all critical points of the given system and investigate the stability of each. dx/dt = y - 1 dy/dt = x^2 - y
*April 4, 2011 by Alex*

**math grade11**

for -2 < x < +3 and f(x) = 3x^2 - 6x a)determine the domain and range of f(x) b) the eqn of f inverse if f(x) is further restricted to 1 < x < 3. i don't know how to these problems i tried everything please help me
*October 25, 2010 by priya *

**Anatomy**

I am working on a research project. I am concerned about my opening paragraph. Could anyone read this to see if it makes sense. My topic is C. Diff. In 2009 according to the CDC and US Deparmtne of Social Secirty there were 2,437,163 people that died that year. During 2009, ...
*August 23, 2012 by Jenifer*

**home economics**

What are the diff.tools, equipments,materials used for farm crop production.
*June 4, 2012 by bing*

**Polynomials**

Im so tired of being frustrated can someone help get the sum diff and product of this problem 3^x ∶ x^2-3^x+ 2
*September 19, 2013 by tela*

**polynomials**

can someone help me with this crazy problem please I have to do the sum diff and product for class x^3- ¡¼2x¡½^2 + 3x-1 ¡Ã x^2- x+4
*September 20, 2013 by Rick *

**polynomials**

Can someone check my answer please i dont know if I am doing this right x^ (2):x= sum (x^2 )+ (x)=x^2+x diff (x^2 )-(x)= (x^2-x) Product (¡¼x)¡½^2 (x)=x^2^x
*September 20, 2013 by Rick *

**math grd 11**

how do u draw an asymtote ? diff btwn set and interval notation? and example plz
*April 15, 2010 by forki*

**Physics**

Please can you help out: 1)The Potential diff across the terminals of a battery is 8.5v when there is a current of 3amps in the cct from the -ve to the +ve terminal. When the current is 2amps in the reverse direction, the potential diff becomes 11volts. a) what is the internal...
*April 17, 2007 by Charles*

**math**

If the roots of the eqn x²-2cx+ab=0 are real and unequal, then prove that the roots of x²-2(a+b)x+a²+b²+2c²=0 will be imaginary.
*July 5, 2014 by tanu*

**maths**

Find the vector eqn of the plane through the points (2,1,-1) and (-1,3,4) and perpendicular to the plane x-2y+4z=10
*August 10, 2014 by abhishek*

**maths**

If the roots of the quadratic eqn x²+px+q=0 are tan 30° and tan 15° respectively, then the value of 2+q-p is-
*July 5, 2014 by jha*

**maths**

If a,b and c € R, then prove that the roots of the eqn 1/(x-a) + 1/(x-b) + 1/(x-c) =0 are always real and cannot have roots if a=b=c.
*July 5, 2014 by tanu*

**math**

Find the vector eqn which passes through (1,1,2) and is parallel to the vector which is perpendicular to both 2i+2j-k and -3i+2j+k
*March 24, 2010 by Edwin*

**math**

The roots of the eqn x^4 - 3x^2 + 5x - 2 = 0 are a, b, c, d, and a^n + b^n + c^n + d^n is denoted by S~n. The equation of the roots a^2, b^2, c^2, d^2 is y^4 - 6y^3 + 5y^2 - 13y + 4 = 0. State the value of S~2 and hence show that S~8 = 6S~6 - 5S~4 + 62.
*September 12, 2006 by joe*

**math**

If a b c are non zero,unequal rational numbers then prove that the roots of the eqn (abc²) x²+ 3a²cx+b²cx-6a²-ab+2b²=0 are rational.
*July 7, 2014 by vaish*

**COMMON PPL MATH MIDTERM**

how do u draw an asymtote ? diff btwn set and interval notation? and example plz
*April 15, 2010 by forki*

**Calculus Help**

use logarithmic diff. to find the derivative of the function. Show steps please! so I can see how it is done. Thank you so much! y=(e^(-x)cos^(2)(x))/(x^(2)+x+1)
*March 18, 2014 by Maho*

**physics**

A particle moves according to the eqn a=-kv where a is acceleration and v is the velocity and k is a constant. If initial speed is V0 find the speed at any instant
*August 19, 2014 by karan*

**equations**

solve the equation 3y square-XY=0 equation(1) 2X-5Y=1 eqn (2)
*November 21, 2011 by emma*

**polynomials**

can someone please help me with this problem I have to get the sum diff and product I keep trying to work it out but i really think im blowing it. x^3- ¡¼2x¡½^2 + 3x-1 ¡Ã x^2- x+4
*September 21, 2013 by Rick *

**math grd 11-midterm tomm**

please explain how do u draw an asymtote ? and whats the diff btwn set and interval notation? and example plz thanks
*April 15, 2010 by just wondering*

**Polynomials check my answer please **

I need help bad i been doing this homework since i got home at 4:00 and am stuck on this problem. X -1 : X-2 =sum (x+1)+(x-2)=(x+x+1-2) diff (x+1)-(x-2)=(x-x-1-2) Product (x-1)(x-2)=(x^2-1)
*September 19, 2013 by johnnie*

**Pre-Calculus**

I want to know how we know if a function is continuas or discontinuos and what are the types and diff if discontinuos functions?
*September 22, 2008 by Mia*

**algebra**

i am three digit number below 100 sum of my digit is 14 and the diff is 4 who am i
*June 11, 2014 by belina*

**Diff Eq**

If y(t)=3e^(t^2)is known to be the solution of the initial value problem y'+p(t)y=0, y(0)=y_0, what must the function p(t) and the constant y_0 be?
*September 7, 2012 by Joe*

**geography**

i did and iv already got that info so i need diff info
*October 11, 2009 by holly*

**Polynomials**

Can someone show me step by step how to get the sum diff and product of this problem x^3- 〖2x〗^2 + 3x-1 ∶ x^2- x+4
*September 19, 2013 by tela*

**Polynomials check my answer**

My brother said I did this wrong can someone check this for me please X Y-1 = sum(x)+ (y-1)=(X+y-1) diff(x)-(y-1)=(x+y+1) Product (x) (x-1) = (xy-1) = (xy-1)
*September 19, 2013 by tela*

**calculus**

Implicit diff. y^2 + 4xy +4y^2=40 2yy'+ _______ + 8y*y=0 I am confused with the 4xy. Would you write this out to be 4x*y'+4y OR 4x*4y' + 4y*4x'? Please help
*October 5, 2014 by Annette*

**math**

find the 5 diff. ways a collection of 100 coins-pennies, dimes, and quarters- can be worth exactly worth $4.99.
*January 27, 2009 by Julie*

**math percentage diff**

a value of 2.40 increased to 4.48 in 5 years. what is the change in percentage each year? this one was difficult to figure out..
*March 24, 2010 by danny*

**Economics**

Microeconomics: Describe the diff. market forms ( I've done that) Under which equlibria and under which circumstances is sustainable profir possible? ( I am lost)
*January 5, 2007 by Angel*

**MATH MID TERM TOMM PPL PLZ HELP**

how do u draw an asymtote ? diff btwn set and interval notation? and example plz
*April 15, 2010 by forki*

**maths**

If the roots of the eqn 1/(x+p) + 1/(x+p) = 1/r are equal in magnitude but opposite in sign, show that p+r=2r and that the product of the roots is equal to (-1/2) (p²+q²)
*July 5, 2014 by tanu*

**chemistry**

0.872g sample containing only NaBr and KBr gives 1.052g AgBr. what's the % of each salt? This is the type of problem that cannot be answered without other information. I think you have made a typo in your problem I worked through it and I get negative numbers for the mass of ...
*December 12, 2006 by hayat*

**CHEMISTRY**

if 16r of METHANOL are reacted wtih an excess of PBr3, how many grams of CH3Br would be formed if there is a 25% yield? eqn; CH2OH + PBr3 --> CH3Br + H3PO3
*February 14, 2010 by ARA*

**maths**

If x²+px+q=0 and x²+qx+p=0,(p not =to q) have a common root. Show that 1+p+q=0; show that their other roots are the roots of the eqn x²+x+pq=0.
*July 7, 2014 by vaish*

**maths**

If one of the roots of the eqn ax²+bx+c=0 be reciprocal of one of the roots of a1x²+b1x+c1=0 then prove that (a a1-c c1)²=(b c1-a b1)(b1 c- a1 b)
*July 7, 2014 by vaish*

**english**

what is autism? autism is a developmental disablity that affects a person's way of communicating with others, their social interaction, and educational performance. how i put this in diff words?
*February 28, 2010 by Anonymous*

**chem**

compute theoretical yield (g) ~2Al+3Cl2->2AlCl3 ~2g Al, 2g Cl2 [ans:2.5g AlCl3] i need the calculation work bcus i got diff from the ans which is 7.12 g.
*July 20, 2011 by lily*

**polynomials help me please**

Im sorry here is the problem rewritten X^3 -2x^3 + 3x-1 : X^2-x+4 I have to get the sum diff and product and it kicking my tail i think i keep doing it wrong can someone please help me
*September 21, 2013 by Rick *

**math**

the no. of real roots of eqn (x-1)POWER 2 + (X-2) POWER 2 +(X-3) POWER 2= 0 IS:
*June 8, 2014 by shish*

**Calculus Help Please!!!**

If x^3 - y^3 =3 , use only implicit diff. to find d^2y/dx^2 . Express your answer in terms of x and y only and write is as a proper fraction that is completely simplified as much as possible.
*April 8, 2014 by Tanya *